Wednesday, November 19, 2008

Life Has Many Moving Parts

Daniel Burd is a teenager. He lives in the town of Waterloo, Ontario, Canada. He is a bright kid. At 16, he is a junior at the Waterloo Collegiate Institute where he gets good grades and also takes part in the student council, sports, and music activities.

Late last year Daniel's science teacher, Mark Menhennet, encouraged him to think up a project he could submit to the annual Canada-Wide Science Fair in Ottawa. Daniel decided to see if he could find some common bacteria that would break down polyethylene plastic bags.

Every year some 500 billion polyethylene plastic bags are manufactured in the world. They are light and strong, easy to handle and quick to throw away. But they degrade very slowly; they take many decades, if not centuries, to decompose. So landfills around the world are filling up with them and millions of square miles of ocean are effectively poisoned by their floating debris.

They decompose slowly, very slowly, but they do decompose. Something in nature is capable of breaking them down chemically and returning their carbon, nitrogen, and oxygen components back into the natural cycles of life. And Daniel set out to figure out just what that "something" was--presumably some microorganism like a species of bacteria with just the right set of enzymes--and to see what could be done to help it "take out" this pernicious trash.

So Daniel ground up plastic bags to a fine powder. And he gathered dirt from local landfills--dirt that might well have the crucial microorganisms. And he let them stew together for several weeks. And, lo and behold, the plastic weighed less--it had been significantly broken down chemically.

To make a long story short, Daniel found two bacteria that could digest polyethylene plastic bags. His project won first prize at the Science Fair; he won a $10,000 prize, a $20,000 scholarship, and international renown.

I said, "To make a long story short," but an important point of this story is that it WAS long. Before he started, Daniel reviewed the world scientific literature to see what had and hadn't been done on this problem, and to decide what techniques might be most likely to succeed. He ground up the plastic with table salt, then washed and filtered the mixture to remove the salt. He dried the plastic grindings and passed them through a strainer so that only uniformly small plastic pellets would be used. He prepared a growth medium of several inorganic chemicals plus a very low concentration of yeast extract. He incubated the plastic powder and dirt in the growth medium for four weeks, reinoculated part of it into clean growth medium for another four weeks, and then did the same for a third, final four-week period. He then took this final enrichment culture and exposed measured pieces of polyethylene bags to it for six weeks, and measured the weight loss of the polyethylene strips (Of course he used "controls" at each stage of this experimental process.)

In other words, his "simple" experiment was not simple at all. It involved a series of knowledgeable and complicated steps. But it worked. There was something in that final enrichment culture that decomposed polyethylene.

But that is not the end of the story. Daniel then went through an elaborate series of careful steps to isolate and identify the bacteria that had done the job--they turned out to be species of Sphingomonasand Pseudomonas. And even that is not the end of the story. Preparing a report of his work and submitting it to the Science Fair involved many more thoughtful and sophisticated steps and many hours of work.

When I was young, I heard the saying, "Build a better mouse trap and the world will beat a path to your door." This turns out to be untrue. I have known several brilliant people in my life whose ideas could have--should have--revolutionized the world. But carrying creative brilliance through to successful application turns out to be a long, complicated process involving many steps, any one of which may be ignored, forgotten, or mishandled and derail the whole process. Life has many, many interdependent moving parts.